A new chiral electrochemical sensor for the enantioselective recognition of penicillamine enantiomers

A new chiral electrochemical sensor has been successfully prepared through chemical linking l-methotrexate (l-Mtx) onto the gold electrode surface. Cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the enantioselective interaction between l-Mtx and Pen enantiomers. The results showed that the l-Mtx-modified gold electrode can selectively recognize penicillamine (Pen) enantiomers using Zn(II) as central ion, and larger response signal was observed from d-Pen owing to the selective formation of Zn complexes. The interaction time between the modified electrode and Pen enantiomers containing Zn(II) was considered. And the electrochemical response of the modified electrode to a series of different concentration of Pen in the presence of Zn(II) was also monitored. In addition, the enantiomeric composition of d- and l-Pen enantiomer mixtures was monitored by measuring the current responses of the sample.